Fully Integrated AND and OR Optical Logic Gates

We propose two novel designs of compact, linear, and all-optical OR and AND logic gates based on photonic crystal architecture. The proposed devices are formed by the combination of the ring cavities and Y-shape line defect coupler placed between two waveguides. The performance of the proposed logic gates has been analyzed and investigated using finite difference time domain method. The suggested design for AND gate offers ON to OFF logic level contrast ratio of not less than 6 dB and the suggested design for OR gate offers transmitted power of not less than 0.5. On top of that, the proposed OR and AND logic gates can operate at bit rates of around 0.5 and 0.208 Tb/s, respectively. Further, the calculated fabrication tolerances of the suggested devices show that the rods radii of the ring cavities need to be controlled with no more than ±10% and ±3% fabrication errors for optical OR and AND gates, respectively. It is expected that such designs have the potential to be key components for future photonic integrated circuits due to their simplicity and small size.